Chandra Observation of the Magellanic Cloud Supernova Remnant 0454–67.2 in N9

A Chandra observation has defined the extent of the SNR 0454-67.2 in the LMC H II region N9. The remnant has dimension 2.′3 × 3.′6 and is elongated in the north-south direction. The brightest emission comes from a north-south central ridge that includes three bright patches. There is good agreement between X-ray and [O III] and [S II] morphology. The remnant is old enough so that optical data give more information about dynamics than do the X-ray data. The supernova (SN) energy release was ≥5 × 1050 ergs, and the age is ~3 × 104 yr. There are several unresolved sources nearby, but none are clearly associated with the remnant. The X-ray spectrum is soft and indicates enhanced Fe abundance in the central region, consistent with a Type Ia SN origin, but a Type II origin cannot be ruled out.